Answer Happy

PHYS 125 -General Physics II - Spring 2020 Homework -2 (Due Feb 10th) - Total -50 points 1. (a) At a distance of d/s from a positive charge, by what factor is the electric potential changed: (1) 1/5, (2) 5. (3) 1/25 or (4) 25? Why? (b) How far from a +2.0 C charge is a point with an electric potential value of 15KV? (c) How much of a change in potential would occur if the point were moved to three times the distance? 2. According to the Bohr model of the hydrogen atom, the electron can exist only in circular orbits of certain radii about a proton. (a) Will a larger orbit have (1) a higher, (2) an equal, or (3) a lower electric potential than a smaller orbit? Why? (b) Determine the potential difference between the two orbits of radii 0.21 nm and 0.48 nm. 3. In problem 2, by how much does the potential energy of the atom change if the electron changes location (a) from the lower to the higher orbit (b) from the higher to the lower orbit (c) from the larger orbit to a very large distance? 4. How much work is required to completely separate two charges (each -1.4 C) and leave them at rest if they were initially 8.0 mm apart? 5. In problem 4, if the two charges are released at their initial separation distance, how much kinetic energy would each have when they are very distant from one another? 91 +40 C 20 cm 20 cm 92 = 140 C 93 -4.0 4C Compute the energy necessary to bring together (from a very large distance) the charges in the configuration shown in the fugure.